New technology is being used to reveal the image that lies beneath a finished Van Gogh painting.

A team of scientists has come up with a new method for seeing beneath Van Gogh's "Patch of Grass" to the woman's face hidden beneath it.
The technique uses a combination of high-intensity x-rays and a working knowledge of old pigments.
It has produced an image of a woman's head, which appears to the be the same model used in a series of portraits and in Van Gogh's "The Potato Eaters" painting.
Van Gogh often re-used canvases, painting over older works, and it is believed that about one-third of his paintings cover earlier images.
The technique could be used to probe what lies beneath other masters' paintings.